Responsive core–shell microgels: Synthesis,characterization, and possible applications

Core–shell microgels are of increasing interest as smart carriers of catalysts, as sensors, or as building blocks for colloidal superstructures. In the context of colloidal assemblies, photonic applications are probably the most promising ones. This progress report presents and discusses the most recent results in this area focusing on the last 2–3 years, and also gives some background information. In addition, potential perspectives of this area will be outlined. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1073–1083     

Effect of low-temperature processing on dry film photoresist properties for flexible electronics

This study presents the mechanical characterization of the dry film photoresist PerMX and its adhesion properties when laminated onto Kapton® E (PI) and Melinex® ST506 (PET). Additionally, the processing temperature, the adhesion strength, and the neutral plane position are investigated and optimized. A relatively low-temperature (85 °C) process is developed to protect the integrity of the polymers with low glass transition temperature and reduce the thermal mismatch stress. Reduction in processing temperature led to a decrement in the adhesion strength. To counteract this unwanted effect, surface treatments (oxygen plasma) are performed on the polymer surface before lamination. Using the latter techniques, adhesion of PerMX to PET (hard bake: 1 h at 85 °C) is increased from 0.07 to 0.26 N mm⁻¹ (variation of 270%). Finally, the mechanical robustness is investigated and increased by tuning the position of the neutral plane, after 50,000 bending cycles and a radius of curvature of 2.5 mm. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013     

New phosphonium salts based on 3-(diphenylphosphino)propanoic and ω-haloalkanoic acids

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Details of Structure Formation During the Induction Period of Spinodal-Type Polymer Crystallization

An unexpected type of primary crystal nucleation is described, involving spinodal decomposition (SD) type microphase separation due to the orientation fluctuations of rigid segments prior to crystal nucleation. This type of mechanism was found by the present authors about 10 years ago, and recently, it was theoretically revealed by Olmsted et al. to be one of three types of primary crystal nucleation: the well-known homogeneous crystal nucleation directly from the liquid–crystal coexistence domain, which occurs at higher temperatures above the binodal temperature T _b , crystal nucleation after binodal microphase separation between T _b and spinodal temperature T _s , and that after SD below T _s . The detailed experimental results for the spinodal-type crystal nucleation, especially the temperature dependence of characteristic wavelength in SD, are explained as well.     

Synthesis and Characterization of New Adhesion Promoter for Grafting Conducting Polymer on Oxide Substrate

For grafting polypyrrole layers on oxidic substrates, the synthesis and characterization of a new adhesion promoter 11‐(pyrrol‐3‐yl) undecyl trimethoxysilane (PyTMS) were described in this article. The oxidation potential of PyTMS was determined by cyclic voltammetry. The grafting behavior of such an adhesion promoter on oxidized surface and chemical deposition of polypyrrole over the modified oxidized surface were studied. The adsorbed layer on the oxidized substrates thus formed was determined by both contact angle measurements and X‐ray photoelectron spectroscopy. Chemical polymerization of terminal pyrrole moieties on such substrates yielded adhesive polypyrrole films, and SEM image showed that the morphology of the polypyrrole films was influenced by the experimental conditions.     

Synthesis of two new cage molecules containing trinitromethyl group

<正>Two new cage compounds,4-trinitroethyl-10-nitro-2,6,8,12-tetraacetylhexaazaisowurtzitane(3) and 4-trinitroethyl- 2,6,8,10,12-pentanitrohexaazaisowurtzitane(4),containing trinitromethyl group were synthesized by a novel method,and their structures were confirmed by IR,~1H NMR,MS and single crystal X-ray.DSC result shows that compound 4 has surprising thermal stability and could be a potential energetic compound.     

干细胞迁移机理的近场扫描光学显微术研究

将内皮细胞生长因子(VEGF)置于甲基纤维素碟中形成VEGF的浓度梯度分布,并将人脐带间充质干细胞(Mesenchymal stem cells,MSCs)于此浓度梯度中培养,观察VEGF能否诱导MSCs定向迁移。应用近场扫描光学显微术(Near-field scanning optical microscopy,NSOM)同时获取了VEGF诱导前后的MSCs的形貌和光学信息。结果表明,近场光学图观测到形貌图上所没有的黑色斑点,分析认为这些黑斑为细胞的黏着斑。近场光学图显示经过VEGF诱导后细胞的黏着斑数量明显增加。同时,对诱导前后干细胞的骨架蛋白进行免疫荧光标记并用共聚焦显微镜进行观察,结果表明细胞骨架由诱导前的无序状态转变为诱导后的有序状态,说明诱导后的干细胞处于迁移状态。光学超微结构图则显示了诱导后干细胞表面的光学细节比诱导前细胞大量增加,出现了大量直径约200 nm的光斑,这是由于细胞表面大量分泌黏附分子等蛋白分子引起的,这些结果为VEGF能够诱导MSCs进行定向迁移提供了实验依据和可视化证明。也表明NSOM不但能提供高分辨的光学分辨率,还可提供生物细胞精细结构的更深层次的光学信息。     

聚对甲基苯胺的合成及其晶体结构

在水相中,FeCl3催化对甲基苯胺聚合合成了对甲基苯胺三分子聚合物——(N,N′E,N,N′E)-N,N′-(2-氨基-5-甲基-2,5-环己二烯-1,4-二亚基)二(4-甲基苯胺)(1),其结构经X-射线单晶衍射仪表征。1属六方晶系,R3空间群,晶胞参数:a=21.116(2),b=21.116(2),c=10.364(2),α=90°,β=90°,γ=120°,Mr=315.41,Z=9,V=4002.1(10)3,Dc=1.178 g.cm-3,μ=0.070 mm-1,λ=0.710 73,F(000)=1 512,R=0.067 8,wR=0.112 6。